Internal-combustion engine



Dec. 31, 1929. J. B. WATSON 1,741,894

INTERNAL COMBUSTION ENGINE Filed Nov. 18. 1926 2 Sheets-Sheet 1 gmemtot James 5. Wmsoq a2, w W

Dec. 31, 1929. J. B. WATSON INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet Filed Nov. 18. 1926 I llllnlllIHHHIIIIHIHHHI James 5. Wafsan,

Patented Dec. 31, 1929 PATENT OFFICE JAMES B. wnrson, or mzrnorr, firemen? INTERNAL-COMBUSTION ENGINE Application filed November 18, 1926. Serial No. 149,126.

. detonation as the case may be; to provide against loss of fresh mixture during the scavenging operation; to provide a two stroke cycle engine having ready startlng characteristics together with the ability to operate evenly at low speed; and to render engines of this type exceedingly compact.

The invention has been shown as applied to an outboard motor such as is commonly used for the propulsion of small boats, but it will be apparent that it may be utilized as the power plant of automobiles and other vehicles, and, in fact, generally for power .pur-

' POSQS.

In the drawings,

Fig. Us a plan view, the flywheel being removed; I Y

F ig. 2 is a view corresponding to Fig. l but on an enlarged scale, parts being broken away to show the construction;

Fig. 3 is a section on line 33 of Fig. 2;

Fig. 4 is a section on line H of Fig. 1;

Figs. 5, 6 and 7. are sections taken, respectively, on lines 5--5, 6-6 and 77 of Fig. 2;

Fig. 8 is a side elevation showing the mannor of joining the auxiliary connecting rods to the main connecting rod.

1 indicates the crankcase, and 2 the crankshaft, the latter comprising the crank arms 3 and crank pin 45 and being supported in bearings 5 and 6, preferably of the thrum type. When the engine is intended for use as an outboard motor, the bearing 5 may be "the larger and carries the weight, while the bearing ti cooperates with a collar 7 formed on the crankshaft to take upward thrusts,

and the crankshaft is extended upwardly through the wall or cover 8 of the crankcase, there to receive the flywheel (the weight of which may be less than that ordinarily used) which has an associated handle 10 or other starting device. The crankshaft and reciprocating parts are preferably balanced by weights 11 formed on or attached to the crank arms in accordance with accepted engineering practice.

In the three cylinder engine shown, the crankcase is faced to form a like number of surfaces 12 at 120 apart upon each of which is mounted a valve seat 13 and a cylinder 14 as by means of bolts 15 passing through flanges 16 on the cylinders and perforated bosses 17 on the valve seats. The cylinders are provided on the intake side with one or more longitudinal grooves or passages 18 formed in the inner wall thereof, and on the opposite side with an exhaust port 19; they are likewise tapped axially to receive spark plugs 20 and are preferably jacketed as art-14: to allow the circulation of cooling Water, although the cooling may be etfected in any well known manner. The outer walls of the jackets may be integral with the cylinders or separate therefrom, as will be obvious. 21., 22., 23 indicate the pistons, these being supplied with a ring or rings 24 and having projecting from the head thereof the circumferentially extending battles 25 which serve to prevent fresh fuel mixture entering the combustion chambers from being blown over into the exhaust ports.

Connected to the piston 21 by means of a pin 30 is a master connecting rod 31 the inner end of which extends about the crank pin 4 and includes a cap 32 secured to the main portion thereof by bolts 33. A suitable bushing or other bearing 34 is, of course, interposed. As best seen in Fig. 8, the cap 32 has aligned perforated bosses or eyes 35 in which are received pins 36 for the auxiliary connecting rods 37 and 38 which correspond to the pistons 22 and 23 and are connected thereto by duplicates of the pin 30. The bolts 33 may, as shown be so arranged as to intersect the holes for the pins 36, thereby serving the additional purpose of retaining the pins in position, but other constructions may, of course, be used.

Each of the valve seats 13, Fig. 5, is prefer ably of rectangular shape and has an opening registering with the inner wall of the corres onding cylinder, as will be more fully un erstood later. The opposite edge portions of the valve seats are shaped to form parallel valve ides 46; and in each pair of guides is slidabfe a valve comprising a main member or plate 47 rforated to receive a ball or s herical bus ing 50 which in turn conforms c osely to the corresponding connecting rod, it being understood that these latter are machined to circular cross section throughout the extent of their movement throu h the associated ball. The valves also inc ude sealing plates 52 bolted together through. the plates 47 and conforming closely to the corres onding ball. For purposes of assembly, the ushings 50 may be split lengthwise as indicated at 53, Fig. 6, the sealing plates also being split as shown at 54, or the connecting rods may be formed in two sections threaded together as will be understood. .Circumferentially extending packings 55 of chrome leather or the like may be carried interiorly of the bushings 50 if desired. The ends of the valve seats are clowd by walls 56 and 57 which are secured to the guides 46 as by the screws 58, thereby preventing the escape of fuel mixture to-the atmosphere. The curvature of the ed 'e of the valve plate 47 at the end adjacent the associated grooves 18 is preferably the same as that of the cylinder wall, and the bottoms of said grooves are likewise preferably arranged on or constituted principally by arcs of the same curvature.

A mixture of fuel andair is supplied to the crankcase in any suitable way, preferably by means of the gasoline nozzle 60, Fig. 4, and inlet pipe 61, the latter of which terminates in an annular chamber .62 extending longitudinally of and surrounding the crankshaft adjacent the bearingfi. A suitable throttle 63 controls the admission of air, and fuel is supplied to the nozzle by a pipe 64 and a float controlled valve (not shown) in the chamber 65, or in any other suitable manner.

It will be noted, Figs. 2 and 7 that the inner walls of the cylinders are shaped at 66 to conform fairly closely to the bafiles 25 when the pistons are at the limit of their outward movement. Therefore, the combustion chamber, the dome of which is otherwise preferably substantiall a portion of a sphere, is better related to t e spark plug 20 than has heretofore been the case. After the baffle 25 in its movement toward the corresponding cylinder head registers with the wall 66, fuel mixture trapped therebetween is expelled forcefully at the ends of the bafile directly into the combustion chamber. There are thus no pockets or remote sections in the combustion chamber such as are ordinarily found in engines of the two cycle typethe tendency to slow burnin or detonation, as the case may be, is reduce and better fuel economy is attained.

The spark plugsare supplied with current from any suitablesource, such as an ordinary ignition coil and timer (not shown) as will be readily understood.

The operation will now be more clearly pointed out: The engine being cranked, fuel mixture is drawn through the pipe 61 and passage 62 into the interior of the crankcase and is there thoroughl mixed by the action of the rotating parts w ich turn clockwise in Fig. 2. Assuming .the parts to be in the position indicated therein, the mixture will be drawn through the port or opening 70 into the space between the piston 22, then on the outward stroke, and its valve, and there will be a tendency to enhance the flow as a result of the action of the rotating parts, including the counterweights, in forcing the fuel and air mixture toward those parts of the crankcase which are farthest from-the crankshaft. By this action and the suction established in the cylinder as the piston moves outwardly, the preliminary compression chamber, by which is meant the chamber between the piston and its valve, will be filled with combustible mixture by the time the valve plate 4L7 has closed the opening 70, and this latter will occur at about the time the piston reaches the limit of its outward movement.

The rotation of the crankshaft continuing, the piston will move toward the axis of the crankshaft and the charge which has been trapped between the piston 22 and its valve will be compressed until the outer face of the piston passes inwardly beyond the outer end 18- of the groove or grooveslS, when it will be blown or rapidly transferred into the combustion chamber. During the next 180 of travel of the piston the mixture will again be compressed, and the ignition being completed as will be understood, the explosion or working stroke of the piston 22 will take place, at the close of which the products of combustion will escape through the exhaust passage 19 into an exhaust manifold (not shown) or directly into the atmosphere as may be desired. The compression of fuel mixture will be increased and the transfer thereof into the combustion chamber will be made more complete by the use of filler blocks 7 5 (but one of which is shownsee Fig. 2) mounted on the corresponding valve and slotted to permit free oscillation of the connecting rod, said blocks preferably having openings 76 opposite the inner ends of the grooves to provide for the escape of mixture which would otherwise be entrapped. The use of these filler blocks will tend to improve the operation particularly under idling conditions, but they may, of course, be omitted.

In the three cylinder engine shown it will be seen that the strokes of the piston 23 will occur 120 later in the revolution of the crankshaft than the corresponding strokes of the piston 22, and that the strokes of the piston 21 will be 120 later than those of the piston 23. That is, there will be overlapping of the power strokes to an extent of which greatly facilitates starting as compared to. the ordinary two cylinder opposed type of two cycle engines used as outboard motorsin .which the cylinders fire in series, giving but one application of power per revolutionof the crankshaft. The difierencebetween the three cylinder engine shown and the ordinary two cylinder two cycle engine referred to, in respect to starting and smoothness of application of power, may therefore be likened to the dinerence between a six cylinder engine and a one cylinder engine of the four cycle type.

Moreover. because of the delivery of fuel mixture to the combustion chamber by compression as pointed out, a greater charge is received than in the case of ordinary two cycle crankcase-compression engines, thus insuring an increased power output, or, putting it another way, permitting a reduction in weight for an engine of like power rating. The forcible delivery of fuel mixture to the combustion chamber likewise tends to insure better scavenging and permits ease of mumin as compared to ordinary engines of this class. It will be noted that the grooves 18 are of but small capacity so that they have little influence on the compression; the flow'of mixture through them also tends to cool the pistons.

While the engine shown is of the three cylinder type, the invention, in so far as it concerns the valve features. is not limited thereto but is of application generally either to single cylinder or multiple cylinders. It has, l1owever, peculiar applicationto installations, as in the case of three cylinder engines, in which, by their inherent characteristics, crankcase compression is precluded. The construction shown is also of minimum length axially of the crankshaft and the placing of the cylinders is such as to permit of securing an unusual amount of power output for the space'oc cupied by the unit.

It will be seen further that the location of the combined valves and packing glands 47, 50, 52 are favorably positioned Withrespect to cooling; that the are constantly in contact with their seats; tlat their acceleration and deceleration is slow and therefore silent in operation; and that they are practically leakproof within wide variations of fit. In fact, slight leakage past the valves or sealing glands will have little effect on the operation. It will be evidentthat the valve and valve seat construction may be modified materially from that shown. i

The parts may be lubricated either by oil mixed with the fuel or in any other suitable manner.

When the engine is used as an outboard motor, it may be'mounted on the rear end of the boat in any suitable manner. In Fig. 1,

for example, the line 7 8 indicates approximately the rear end of a boat of the square stern type, from which it will be men that the carburetor and other accessory parts, such as the ignition coil (not shown), may be arranged conveniently to the operator.

I claim: j

1. An internal combustion engine of the two-stroke cycle type comprising a rotatable crankshaft including a crank, a fixed crankcase, a plurality of cylinders mounted on the crankcase and extending radially about the v crankshaft having a crank, a fixed crankcase in which the crankshaft is mounted, three cylinders radially disposed about said crankcase and spaced substantially 120 apart, pistons therefor, swingable connecting rods joining the pistons to said crank, and means for utilizing the working strokes of said piston to compress a mixture of fuel and air for the next working stroke of the corresponding piston, said means including a valve for each cylinder positively actuated by the corresponding connecting rod to trap such mixture between the corresponding valve and piston, and means to convey the mixture thus compressed to the interior of the corresponding cylinder for combustion therein.

3. An internal combustion engine of the two-stroke cycle type including a cylinder, 2. piston reciprocable therein, there being a passage through Which a mixture of fuel and air enters the cylinder at the end of the working stroke of the piston, the cylinder having an exhaust opening on the side thereof diametrically spaced from said passage, the piston including a bafile for preventing the mixture from passing directly across the cylinder from said passage to said exhaust opening,

tary to the side of said baflle nearest said passage.

4.. An internal combustion engine of the two-stroke cycle type including a cylinder ha'vinga dome symmetrical about the axis of said cylinder except as hereinafter indicated,

a spark plug in said cylinder substantially coaxially therewith, a piston for said cylinder, means for admitting air and fuel to said cylinder at the end of the working stroke of said piston and at one side of the latter,'means for allowing products of combustion to simultaneously escape at the other side of said piston, the piston including a baflle adjacent the side at which the air and fuel enter, the dome bein shaped to substantially conform to the si e of said' bafile nearest to the side of the cylinder at which the fuel and air enter.

5. A two-stroke cycle internal combustion engine comprising a cylinder forming a combustion chamber, a piston for said cylinder, said'piston having a baflle, the inner wall of said cylinder being grooved on one side of said bafile'only and for a greater-(length than said piston so as to overlap the latter at the end of the power stroke, and means cooperat ing with said piston to compress a mixture of fuel and air during said power stroke whereby said mixture isgdischarged through the groove into the combustion chamber substantially at the end of the power stroke.

6. A two-stroke cycle internal combustion engine comprising a cylinder having a com bustion chamber, apiston reciprocable therein and comprising a bafile, a crankshaft, a connecting rod joining the piston and the crank of said shaft, a valve associated with the connecting rod and arranged to cooperate with the cylinder and piston to trap a charge of mixed fuel and air during the power stroke of the piston, the cylinder being grooved in its inner Wall on one side of the baffle only to allow the trapped charge to escape into the combustion chamber substantially at the end of said power stroke.

7, An internal combustion engine of the two-stroke cycle type comprising a fixed crankcase, a rotatable crankshaft, a cylinder having a firing end, a piston for the cylinder, a valve slidable transversely of the axis of the cylinder and intermittently opening and closing communication between .the crankcase and the space in the cylinder at the end thereof nearest the crankshaft to allow a mixture of fuel and air from the crankcase to pass into said space during the compression stroke of the piston and to trap said mixture therein during the working stroke of the dpiston whereby the mixture is compresse and means for transferring said mixture into the firing end of the cylinder substantially at the close of said working stroke.

8. An engine of the type set forth including a rotatable crankshaft, a fixed crankcase in which the crankshaft is mounted, cylinders disposed radially about said crankshaft and having their axes intersecting the axis of the crankshaft at acommon point, pistons therefor connected to said crankshaft, and means for utilizing the working strokes of each of said pistons to compress air and fuel mixture for the next working stroke of the corresponding piston.

9. An engine of the type described comprising a fixed crankcase, a crankshaft rotating cylinder,

ablymounted therein, a cylinder carried by the crankcase, a piston therefor connected to the crankshaft, means for supplying fuel mixture to the crankcase proximate the crankshaft, a valve adapted to open and close com-- munication between said crankcase and the inner end of the cylinder whereby said fuel mixture after being agitated in the crankcase is allowedto escape into said inner end of the cylinder during the compression stroke of the piston and whereby said mixture is afterward com ressed by the piston during its working stro e, means for thereafter transferring said mixture from the inner end of the cylinder to the outer end thereof at the end of said working stroke, and means for subsequently igniting the mixture.

10. An engine of the class set forth comprising a rotatable crankshaft having a crank, a fixed crankcase, a plurality of cylinders mounted thereon and extending radially of the crankshaft, pistons therein connected to. the crank, means for admitting mixture of fuel and air for said cylinders to said crankcase proximate to said shaft, and substantially flat valve means reciprocable in a plane at right angles to the axis of the correspondermitting the escape of said mixture from t e crankcase into each cylinder during the outward stroke of the corresponding piston.

11. An outboardmotor comprising an internal combustion engine of the two-stroke cycle type comprising a crankshaft inclined to the horizontal and having a crank, a fixed crankcase in which said crankshaft is rotatably mounted, a plurality of cylinders mounted on the crankcase and extending radially about the crankshaft, pistons therein, swingable connecting rods joining said piston and crank, means for supplying'a mixture of fuel and air through said crankcase in succession to said cylinders, said means including a valve for each cylinder cooperating with the corre sponding cylinder and piston to cause compression of mixture by said piston during the -working stroke thereof, said valves being movable by the corresponding connecting rod transversely of the axis of the corresponding cylinder, and means acting on the upper end portion of the crankshaft for cranking the engine.

12. An internal combustion engine of the two-stroke cycle type including a crankshaft inclined to the horizontal and having a crank, a fixed crankcase in which the crankshaft is mounted, three cylinders radially disposed about said crankcase and spaced substantially 120 apart, pistons therefor, means for connecting the pistons to said crank, means for utilizing the working strokes of said pistons to compress a mixture of fuel and air for the next working stroke of the corresponding piston, and means acting on the upper end portion of the crank shaft for cranking the engine. n

13. An internal combustion engine of the two-stroke cycle type comprising a crank chamber, a cylinder attached thereto, a piston in said cylinder, a rotatablecrankshaft in said crank chamber, a connectingrod for said piston and crankshaft, means for supplying fuel mixture to said crank chamber, a valve actuated by said connecting rod and interposed between said cylinder and said crank chamber, and a port leading from the crank chamber to the inner end of said cylinder on the side of said valve toward which the ads jacent side of the crankshaft turns.

14. In internal combustion engines of the type wherein preliminary compression of the fuel mixture is effected between the piston and a valve moving synchronously therewith and transversely with respect to the axis of said piston, a crank chamber, and a port connecting the crank chamber and the cylinder on the side of said valve toward which it moves in the compression stroke of the piston.

15.An internal combustion engine of the two-stroke cycle type comprising a crank chamber, a cylinder attached thereto, a piston in said cylinder, a rotatable crankshaft in said crank chamber, aconnectin rod for said iston and crankshaft,'means or supplying uel mixture to said crank chamber, a valve movable by said connecting rod transversely of the axis of said piston and controlling communication between said cylinder and crank chamber and means within the crank chamber movable with the crankshaft for agitating the fuel mixture and tending to force it into the outer circumferential portions of the crank chamber.

16. An internal combustion engine of the type set forth comprising a crankcase and a crankshaft including a crank rotatable therein, said crankcase forming a plurality of surfaces spaced from each other angularly about the axis of the crankshaft, cylinders arranged radially of the crankcase and having combustion chambers at the outer ends thereof, valve seats clamped between the cylinders and said surfaces, pistons in said cylinders, connecting rods joining said pistons and said crank, valvesslidable in said seats at right angles to the axis of the corresponding cylinder to open and close communication between the crankcase and the inner ends of said cylinders, said valves being actuated by the cor responding connecting rods, means for supplying fuel and air to said crankcase, the parts being so constructed and arranged that mixture passing from said crankcase to each cylinder on the outward stroke thereof is subsequently compressed between said cylinder and said valve on the inward stroke of said cylinder, and means for transferring said compressed mixture from the inner end .thereof, valve seats, one interposed between each cylinder and the corresponding surface on the crankcase, common means for securing each cylinder and the corresponding valve seat on said crankcase, pistons in said cylinders, connecting rods joining said pistons and said crank, valves slidable in said seats at right angles to the axis of the corresponding cylinder to open and close communication between the crankcase and the inner ends of said cylinders, said valves being actuated by the corresponding connecting rods, means for supplying fuel and air to said crankcase, the

parts being so constructed and arranged that mlxture passing from said crankcase to each cylinder on the outward stroke thereof is subsequently compressed between said cylinder and said valve on the inward stroke of said cylinder,'and means for transferring sald compressed mixture from the inner end of each cylinder to the combustion chamber thereof.

18. An internal combustion engine of the two-stroke cycle type comprising a crankcase, a crankshaft inclined to the horizontal and rotatable in said crankcase, said crankshaft projecting both above and below said crankcase and having a crank therein, a starting device fixed to the projecting upper end of'the crankshaft, more than two cylinders extending radially from said crankshaft and spaced substantially equally apart, pistons therefor, connecting rods joining the pistons to said crank, means for supplying a mixture of fuel and air to said crankcase proximate the axis of the crankshaft and below said starting device, said means including a carburetor positioned in the angle between two of said cylinders, and means for transferring said mixture from said crankcase in succession to said cylinders, said last named means including a valve for each cylinder movable by the corresponding connecting rod and cooperating with the corresponding cylinder and piston to cause compression of said mixture by said piston during the working stroke thereof.

' 19. An internal combustion engine of the two-stroke cycle type including a rotatable crankshaft having a crank, a relatively fixed crankcase in which the crankshaft is mounted,

cylinders radially disposed about said crankcase and spaced equally apart, pistons therefor, swingable connecting rods joining the pistons to said crank, and means for utilizing the working strokes of said pistons to compress a mixture of fuel and air for the next working stroke of the corresponding piston, said means including a valve for each cylinder positively actuated by the corresponding connecting rod to trap such mixture between the corresponding valve and piston, and means to conve the mixture thus compressed to the interior of the correspondingcylinder for combustion therein.

In testimony whereof I aflix m si ature.

' JAMES .'w A1 s oN. 

